How to control the temperature rise of transformer

As the core equipment in power system, the running state of transformer directly affects the security and stability of power system. In the process of transformer operation, due to the existence of copper loss and iron loss, a lot of heat will be generated, which will lead to the rise of transformer temperature. If the temperature rise is too high, it will not only accelerate the aging of insulation materials, reduce the service life of transformers, but also cause failures and even fires. Therefore, controlling the temperature rise of transformer is an important link to ensure its safe operation.

First, the cause analysis of transformer temperature rise

The temperature rise of transformer mainly comes from two aspects: one is the copper loss caused by the current flowing through the conductor in the winding, and the other is the eddy current loss and hysteresis loss (that is, iron loss) caused by the alternating magnetic field. Both losses will be converted into heat, which will raise the internal temperature of the transformer. In addition, factors such as high ambient temperature, poor ventilation and heavy load will also aggravate the temperature rise.

Second, the main measures to control the temperature rise of transformer

1. Reasonable selection of transformer capacity
In the design and selection stage, the transformer capacity should be reasonably configured according to the actual load demand to avoid long-term overload operation. Generally speaking, the optimal load rate of transformer should be between 60% and 80%, which can not only ensure the efficiency, but also effectively control the temperature rise.

2. Adopt high-quality materials and structural design.
Choosing low-loss silicon steel sheet, high-conductivity copper material, optimized winding structure and heat dissipation structure can significantly reduce the loss of transformer, thus reducing the heat generation. For example, dry-type transformers often adopt air convection heat dissipation design, while oil-immersed transformers use transformer oil for cooling.

3. Strengthen daily operation management and monitoring.
By installing a temperature monitoring device, such as an infrared thermometer or an optical fiber temperature measurement system, the operating temperature of the transformer can be monitored in real time. Once the temperature is abnormal, measures should be taken immediately, such as reducing the load, checking the cooling system or arranging maintenance.

4. Improve heat dissipation conditions
Ensure good ventilation around the transformer and avoid the influence of direct sunlight or heat source. For oil-immersed transformers, it is necessary to regularly check whether the cooling system (such as fan, radiator, oil pump, etc.) is operating normally to ensure the smooth circulation oil circuit.

5. Regular maintenance and overhaul
Regularly inspect and replace transformer oil to keep the oil clean and improve the cooling efficiency. At the same time, check whether the winding and terminal are loose to prevent local overheating caused by excessive contact resistance.

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Controlling the temperature rise of transformer is not only the premise to ensure its normal operation, but also the key to prolong its service life and improve the reliability of the system. Through scientific design, reasonable operation management and effective maintenance measures, the temperature rise can be effectively suppressed and the transformer can work stably in a safe temperature range. With the development of smart grid, the real-time early warning and intelligent regulation of transformer temperature rise can be realized with the help of intelligent monitoring system in the future, and the operation and management level can be further improved.